Abstract: In downlink of WCDMA, orthogonal variable spreading factor (OVSF) codes are used as channelization codes to distinguish different physical channels in order to decrease MAI and support variable bit rate services. So the assignment scheme and allocation algorithm of OVSF affect the performance of the whole network directly. In this paper, the disadvantages of DCA are analyzed and a multi-codes assignment algorithm supporting reassignment of codes is proposed. The simulation results show that this algorithm can decrease the code fragments on the OVSF code tree and reduce the impact of reassignment process to system efficiently maintaining the utilization ratio of the downlink bandwidth at the same time.

Key words: WCDMA, RRM, Orthogonal variable spreading factor (OVSF), Code blocking ratio

摘要： WCDMA的下行链路中，OVSF码被用作区分不同物理信道的信道化码，以最大程度降低UE的多址接入干扰(MAI)，并提供对可变速率的支持。所以OVSF码的分配策略及算法直接影响网络的整体性能。该文分析了DCA算法的不足之处并提出了一种支持重分配的多码分配算法。仿真结果表明，该算法能在保持下行链路带宽利用率的同时，有效地减少OVSF码树的碎片并减轻重分配给系统带来的影响。

关键词: WCDMA, 无线资源管理, OVSF, 码阻塞

CLC Number: 

• TP929.533